The present invention relates to a rotary machine, such as a refrigerating compressor for use in a vehicle air conditioning apparatus, and more particularly, to a method of adjusting movable amount in a direction of a rotary axis of a rotary body for use in the rotary machine to a predetermined amount.
Japanese Unexamined Patent Publication No. 2001-263228 as a referenced publication discloses a piston-type refrigerating compressor for use in a vehicle air conditioning apparatus. (See pages 7 to 10 of the referenced publication and FIGS. 1 to 3 of the referenced publication). In FIGS. 7A and 7B, a left side of each drawing is a front side and a right side thereof is a rear side. Referring to FIG. 7A, a rotary shaft 81 is rotatably supported in a housing 80 of the refrigerating compressor and is slidable along the direction of a rotary axis L thereof. In the housing 80, a compression mechanism is accommodated and includes a lug plate 82, a swash plate 83 and a piston 84. An engine, which serves as a drive source for use in a vehicle, drives the rotary shaft 81 and thereby the lug plate 82 and the swash plate 83 are rotated together with the rotary shaft 81. Therefore, a piston 84 is reciprocated in a cylinder bore 85 and thereby refrigerant gas is compressed. In the housing 80, a sealing member 98, which is placed on a side of the rotary shaft 81 that protrudes outside the housing 80, thereby prevents refrigerant from leaking along the rotary shaft 81 outside the housing 80.
The refrigerating compressor includes means for restricting movable amount of the rotary shaft 81 in tho direction of tho rotary axis L to a predetermined amount that is extremely short, such as a length of 0.1 mm. The means is hereinafter referred to movement restricting means. Also, the movable amount is hereinafter referred to a thrust clearance. Specifically, frontward sliding movement of the rotary shaft 81 in the direction of the rotary axis L is restricted in a slate that the lug plate 82 that is integrated with the rotary shaft 81 contacts with an inner wall surface 87 of the housing 80 through a thrust bearing 86. On the other hand, rearward sliding movement of the rotary shaft 81 in the direction of the rotary axis L is restricted when an outer circumferential portion 88a of a rear end surface 88 of the rotary shaft 81 contacts with a front end surface 90 of an adjustable member 89 that is fixedly press-fitted into the housing 80.
Thus, when the thrust clearance of the rotary shaft 81 is adjusted to the predetermined amount extremely short, sealing defect of the sealing member 98 caused by sliding movement of the rotary shaft 81 is prevented.
As shown in FIG. 7B, in the prior art, when the adjustable member 89 is press-fitted into the housing 80, and when the thrust clearance of the rotary shaft 81 is adjusted to a predetermined amount X1, a jig 92 that is exclusive for press fit is used.
Specifically, the jig 92 includes a body 93 that has cylindrical shape and a clearance adjusting part 94 for adjusting a clearance. The clearance adjusting part 94 extends from the front end surface of the body 93. The diameter of the clearance adjusting part 94 is smaller than that of the body 93. In the front end surface of the body 93, a part of the front end surface of the body 93 that forms a step by the body 93 and the clearance adjusting part 94 is a pressing portion 95. In the jig 92, the length of the clearance adjusting part 94, that is, the distance in the direction of the rotary axis L between the pressing portion 95 and the front end surface of the clearance adjusting part 94, is sent to be equal to the sum of thickness Y of the adjustable member 89 and the predetermined amount X1 of the thrust clearance of the rotary shaft 81.
A through hole 96 extends through the adjustable member 89 in the direction of the rotary axis L. When the jig 92 is used, the clearance adjusting part 94 is inserted from the rear side of the through hole 96. In this state, the pressing portion 95 is pressed against the rear end surface 97 of the adjustable member 89. Thereby, the adjustable member 89 is pressed toward the rotary shaft 81 and the front end surface of the clearance adjusting part 94 is pressed to a middle portion 88b of the rear end surface 88 of the rotary shaft 81.
Therefore, the rotary shaft 81 is frontward pressed in the direction of the rotary axis L, and the frontward sliding movement in the direction of the rotary axis L of the rotary shaft 81 is restricted in the state that the lug plate 82 contacts with the inner wall surface 87 of the housing 80 through the thrust bearing 86. In this state, the clearance adjusting part 94 of the jig 92 protrudes from the front end surface 90 of the adjustable member 89 by the predetermined amount X1 toward the rotary shaft 81. Therefore, the distance between the rear end surface 88 of the rotary shaft 81 and the front end surface 90 of the adjustable member 89, that is, the thrust clearance of the rotary shaft 81, is set to the predetermined amount X1.
In the method of adjusting the thrust clearance of the rotary shaft 81 according to the aforementioned prior art, however, the clearance adjusting part 91 of the jig 92 is contacted with the middle portion 88b of the rear end surface 88 of the rotary shaft 81. That is, the clearance adjusting part 94 of the jig 92 is contacted with the middle portion 88b of the rear end surface 88 different from the outer circumferential portion 88a of the rear end surface 88, which contacts with the adjustable member 89. Therefore, manufacturing quality of the rear end surface 88 of the rotary shaft 81, that is, manufacturing quality of the outer circumferential portion 88a and the middle portion 88b, affects the thrust clearance of the rotary shaft 81. Thereby, the thrust cl aranc of the rotary shaft 81 is not set in high accuracy.
Namely, in a state of FIG. 7B, even if the distance between the middle portion 88b of the rear end surface 88 and the front end surface 90 of the adjustable member 89 is set to the predetermined amount X1, the distance between the outer circumferential portion 88a that is an actual contacting portion and the front end surface 90 is deviated from the predetermined amount X1 owing to the manufacturing quality of the rear end surface 88.
Also, in the method of adjusting the thrust clearance of the rotary shaft 81 according to the aforementioned prior art, the pressing portion 95 of the jig 92 is contacted with the rear end surface 97 of the adjustable member 89. In addition, the clearance adjusting part 94 of the jig 92 is inserted into the adjustable member 89 and is contacted with the rear end surface 88 of the rotary shaft 81. Therefore, manufacturing quality of the adjustable member 89 also affects the thrust clearance of the rotary shaft 81. Especially, the manufacturing quality of the thickness of the adjustable member 89 affects the thrust clearance of the rotary shaft 81.